I don't see you having a problem. I am using the Niles SSVC-4 in three of my restaurants with two pairs of speakers each. The volume control is a great feature for setting each pair according to the rooms acoustics.

Russel-the answer to your question is not as easy as it might seem because it depends on the speakers you are driving. Speakers are usually rated btw 4 and 8 ohms. If all 4 speaker sets you are driving are rated at 8 ohms you should be fine-even if they are 6 ohms. If they are more difficult than that I don't know. It also depends on how loud you what to play them. If you had 4 sets of difficult speakers and you were going to rock the rafters with all four? Well, maybe not. I actually have two of these Niles switchers-both have performed flawlessly, and there are several features that are great-one I like is the little speaker connectors. The other is less obvious but more important and that is that the units are "impedance matching". That means that if your speakers have different impedances, it matches them so that the amplifier sees only one impedance-which is important for some reason. I remember a couple friends that blew their amps up in high school by driving two sets of speakers (of different impedances) with the "A" and "B" outputs of their amps run simultaneously. The simple answer is yes, you'll be OK. I run 4 sets of speakers simultaneously with a 140 w amp and only turn it up a third of the way. Happy listening! Bill

Yes - if you have the receiver has the comparability - you set the volume on the receiver, and when you control the Blu-toothed / wifi device... You are adjusting the volume output to the receiver. You are not adjusting the master volume... Just signal to the input. Works done for the most part

I have my Ipod hooked up to my receiver and I can adjust the volume through my iPod. It will adjust the level equally to all the speakers you have hooked up and if one area is too loud or soft you adjust individually by the volume on the Miles unit. The volume on the miles is not as delicate as a volume on your stereo or iPod. The Miles clicks in intervals. I have not found this to be a problem at all.

My Niles SSVC-4 is used downstream of a Pioneer AV receiver to operate a second zone of ceiling speakers in four different rooms. The second zone allows simultaneously play of the same or a different input from the AV receiver, which is fully IPod controlled. According to my Pioneer AV instructions, a second amp is required to power the second zone. I use a classic Marantz 100 Watt receiver. Changes in the Marantz receiver volume do raise / lower the speaker volume downstream of the Niles SSVC-4. The Marantz receiver volume control is manual, but I am sure that if the Marantz receiver had IPod volume control capability it would work similarly. Manual controls on Niles SSVC-4 do control speakers on / off and volume level by room, but raising the Marantz receiver master volume raises the volume in all of the room, regardless of the Niles SSVC-4 setting. I hope this helps.